ИСТИНА

In the XXI century the number of goby species recognized in the Ponto-Caspian basin significantly increased. Several Mediterranean species (Gobius cruentatus, G. xanthocephalus, Gammogobius steinitzi, Millerigobius macrocephalus, Pomatoschistus bathi, Chromogobius zebratus) were first discovered in the Black Sea. The reproducing population of accidentally introduced Pacific species Tridentiger trigonocephalus was found in the Crimean area. The mtDNA cytochrome b gene analysis revealed that the genus Proterorhinus is not monotypical but includes at least three morphologically similar species: P. marmoratus, P. nasalis, and P. semilunaris. In addition to three previously accepted freshwater Caucasian goby species (Ponticola constructor, P. cyrius, and P. rhodioni) two new species were described from the Black Sea in Turkey (P. rizensis and P. turani) and the last one - from the Iranian coast of the Caspian Sea. New tadpole-goby Benthophilus ragimovi was described from the Middle Caspian. Our recent karyological and molecular-genetic studies proved the validity of Ponticola iljini, previously included in the synonyms of P. gorlap. Both these species are very similar in external morphology, but have different karyotypes and form separate lines of the same subclade in the phylogenetic gobiid tree, obtained for cytochrome b gene, and thus they represent cryptic species.